Welcome to the European

2005

consortium

2009

Nanophotonic and Nanoelectronic Devices from Oxide Semiconductors

Abstract:

Developing nanotechnologies has become an objective of utmost strategic importance for reinforcing the competitiveness European industry. Whereas the top-down approach for the fabrication of nanostructures becomes exponentially more expensive, the bottom-up approach utilising self-organisation of nanostructures is a simple and productive way to achieve devices with very small lateral dimensions in an extremely parallel process. For application of self-organisation on an industrial scale, however, the “automatic” self-organised formation of nanostructures has to be controllable precisely. Among the many materials exhibiting self-organisation, oxide semiconductors, e.g. Zinc Oxide (ZnO) and related compounds, are a very interesting material family. A wide variety of self organised ZnO nanostructures have been realised recently (nanopillars, nanowires, nanobelts,..) that could have novel applications in optoelectronics, sensors, transducers etc. ZnO is a wide bandgap semiconductor with a record value of exciton binding energy and extremely large oscillator strength, which make it a particularly good candidate for UV nanophotonics at room temperature. In addition, oxides can also be used for chemical and gas sensing applications and the large surface area of nanostructures is one of their attractive aspects in this regard. ZnO based devices will find their application in areas such as communication, security environment or biomedical sciences. One particular attractive aspect of our project is that, unlike some other competing materials, ZnO based nanodevices can be fabricated on a variety of different substrates, including silicon or flexible polymer substrates, which makes them compatible with existing silicon technology and organic electronics and optoelectronics, an emerging field in rapid expansion. The use of flexible substrates with inorganic semiconductors is a particular and new aspect of nanophotonic devices proposed here. Thus, the objective of this project is to develop and optimise ZnO nanostructures that will give rise to a variety of nanodevices. Among the many potential applications, we have chosen to demonstrate devices with application in two specific sectors, optoelectronics, with a particular emphasis on lighting technology, and gas sensing.

Partners:

Göteborg University / Linköping University; PEP, SE-412 96 Göteborg, Sweden

Technische Universitaet Braunschweig; Hans-Sommer-Straße 66, D-38023 Braunschweig, Germany

Université Joseph Fourier - Grenoble; 621, avenue Centrale, F-38043 Grenoble, France

University Leipzig Semiconductor Physics Group; Linnéstr. 5, D-04103 Leipzig, Germany

National Centre for Scientific Research "DEMOKRITOS"; Agia paraskevi, 15310 Attiki, Greece

OSRAM OPTO SEMICONDUCTORS GMBH; Leibnizstrasse 4, D-93055 Regensburg, Germany

LightLab Ltd.; Smedjegatan 6, SE-13134 Nacka, Sweden

Publications:

2008

A. Bakin, Alexander Wagner, Eva Schlenker, Bianca Postels, Mohamed Al-Suleiman, Arne Behrends, Abdel-Hamid Elshaer, Vladimir Petukhov, and A. Waag, ZnO Nanostructures and Thin Layers for Device Applications, ECS Transactions, Volume 16(12) page 107 ff, The Electrochemical Society 2008

E.Schlenker, A.Bakin, T.Weimann, P.Hinze, D.H.Weber, A.Gölzhäuser, H-H.Wehmann, A.Waag On the Difficulties in Characterising ZnO Nanostructures, Nanotechnology 19 (2008) 365707

D. H. Weber, A. Beyer, B. Völkel, A. Gölzhäuser, E. Schlenker, A. Bakin, and A. Waag, Determination of the specific resistance of individual freestanding ZnO nanowires with the low energy electron point source microscope, Virtual Journal of Nanoscale Science and Technology 17(2)(2008) (reprint from APL)

Bakin, J. Kioseoglou , B. Pecz, A. El-Shaer, A.-C. Mofor, J. Stoemenos, A. Waag Misfit reduction by a Spinel layer formed during the epitaxial growth of ZnO on Sapphire using a MgO buffer layer, J. Crystal Growth, 308, 2007, pp. 314–320

2007

D. Hofstetter, Y. Bonetti, F. R. Giorgetta, A-H. El-Shaer, A. Bakin, A. Waag, R. Schmidt-Grund, M. Schubert, and M. Grundmann. Demonstration of an ultraviolet ZnO-based optically pumped 3rd order distributed feedback laser, Appl. Phys. Lett. 91, 2007, 111108

V. Petukhov, A. Bakin, A.-H. El-Shaer, A.-C. Mofor, and A. Waag. Etch-Pit Density Investigation on Both Polar Faces of ZnO Substrates, Electrochemical and Solid-State Letters, vol. 10, n. 12 2007

M. Al-Suleiman, A. El-Shaer, A. Bakin, H.-H.Wehmann and A.Waag. Optical investigations and exciton localization in high quality Zn1-xMgxO–ZnO single quantum wells, Appl. Phys. Lett. 91, 2007, 081911

B. Piechal, J. Yoo, A-H. Elshaer, A-C. Mofor, G-C. Yi, A. Bakin, A. Waag, F. Donatini, Le Si Dang. Cathodoluminescence of single ZnO nanorod heterostructures, Phys. Stat. sol. (b), 1-4, 2007

D. H. Weber, A. Beyer, B. Völkel, A. Gölzhäuser, E. Schlenker, A. Bakin, A. Waag: Determination of the specific resistance of individual freestanding ZnO nanowires with the low energy electron point source microscope, APL, 2007, accepted,

C. Bekeny, T. Voss, J. Gutowski, B. Postels, M. Kreye, A. Waag Optical properties of ZnO nanorods realised by aqueous chemical growth Superlattices and Microstructures 42, 398-402 (2007)

B. Postels, H-H. Wehmann, A. Bakin, M. Kreye, D. Fuhrmann, J. Blaesing, A. Hangleiter, A. Krost and A. Waag. Controlled low temperature fabrication of ZnO nanopillars with a wet-chemical approach, Nanotechnology, *18*, 195602 (2007)

C. Bekeny, T. Voss, B. Hilker, R. Hauschild, H. Kalt, B. Postels, A. Bakin, A. Waag, and J. Gutowski, J. Appl. Phys. 102, 2007, 044908

A.Bakin, A. El-Shaer, A.C.Mofor, M. Al-Suleiman, E. Schlenker, and A.Waag. ZnMgO-ZnO Quantum Wells Embedded in ZnO Nanopillars: Towards Realisation of Nano-LEDs, Phys. Stat. Solidi (c), vol. 4, n1, 2007, pp. 158-161

A. Bakin , A. Che Mofor, A. El-Shaer, and A. Waag. Vapour Phase Transport Growth of ZnO Layers and Nanostructures , J. Superlattices and Microstructures, Elsevier, Volume 42, Issues 1-6, 2007, pp. 33-39

A. El-Shaer, A. Bakin, M. Al-Suleiman, S. Ivanov , A. Che Mofor, and A. Waag Growth of wide band gap wurtzite ZnMgO epilayers on (0001) Al2O3 by radical-source molecular beam epitaxy , J. Superlattices and Microstructures, Elsevier, Volume 42, Issues 1-6, 2007, pp. 129-133

A. C. Mofor, A. S. Bakin, B. Postels, M. Suleiman, A. Elshaer, A. Waag. Growth of ZnO Layers for Transparent and Flexible Electronics , J. Superlattices and Microstructures, Elsevier, 2007 (in press)

A. El-Shaer, A. Bakin, A. Che Mofor, J. Stoimenos, B. Pécz, and A. Waag. Layer by layer growth of ZnO on (0001) sapphire substrates by radical-source molecular beam epitaxy , J. Superlattices and Microstructures, Elsevier, Volume 42, Issues 1-6, 2007, pp. 158-164

S.V. Ivanov, A. El-Shaer, T.V. Shubina, S.B. Listoshin, A. Bakin, and A. Waag. Growth kinetics and properties of ZnO/ZnMgO heterostructures grown by radical-source molecular beam epitaxy , Phys. Stat. Solidi (c) 4, No. 1, 2007, pp. 154–157

E. Schlenker, A. Bakin, B. Postels, A.C. Mofor, M. Kreye, C. Ronning, S. Sievers, M. Albrecht, U. Siegner, R. Kling, A. Waag. Magnetic characterisation of ZnO doped with Vanadium , J. Superlattices and Microstructures, Elsevier, Volume 42, Issues 1-6, 2007, pp. 236-241

A. C. Mofor, A. Bakin, U. Chejarla, E. Schlenker, A. El-Shaer, G. Wagner, N. Boukos, A. Travlos and A. Waag. Fabrication of ZnO Nanorod-based p-n Heterojunction on SiC Substrate, J. Superlattices and Microstructures, Elsevier, vol. 42, iss. 1-6, 2007, pp. 415-420

A. El-Shaer, A. Bakin, E. Schlenker, A. C. Mofor, G. Wagner, S. A. Reshanov and A. Waag Fabrication and characterization of n-ZnO on p-SiC heterojunction diodes on 4H-SiC substrates, J. Superlattices and Microstructures, Elsevier, Volume 42, Issues 1-6, 2007, pp. 387-391

B. Postels, M. Kreye, H.-H. Wehmann, A. Bakin, N. Boukos, A. Travlos, D. Fuhrmann, A. Hangleiter, A. Waag Selective growth of ZnO nanorods in aqueous solution , J. Superlattices and Microstructures, Elsevier, 42, 2007, pp. 425-439

A. C. Mofor, A. S. Bakin, A. El-Shaer, D. Fuhrmann, F. Bertram, A. Hangleiter, J. Christen and A. Waag Vapour Transport Growth of ZnO Nanorods, Appl. Phys. A, DOI: 10.1007/s00339-007-3961-5 (2007)

El-Shaer, A. Bakin, A. Che Mofor, J. Bläsing, A. Krost, J. Stoimenos, B. Pecz, M. Kreye, A. Waag H2O2-Molecular Beam Epitaxy of high quality ZnO , Journal Applied Physics A: Materials Science and Processing, Springer 88, 2007, 57

A.C. Mofor, F. Reuß, A. El-Shaer, R. Kling, E. schlenker, A. Bakin, H. Ahlers, U. Siegner, S. Sievers, M. Albrecht, W. Schoch, N. Izyumskaya, V. Avrutin, W. Limmer, J. Eisenmenger, Th. Mueller, P. Ziemann, and A. Waag Magnetism in Zn(TM)O layers and nanorods grown on Sapphire , Journal Applied Physics A: Materials Science and Processing, Springer, vol. 88, 2007, pp. 161-166

M. Willander et al., International Bhurban Conference on Applied Science and Technology, Islamabad, Pakistan, 8-11 Jan., 2007 (Invited talk).

M. Willander et al., SPIE- Photonic West, 20-25 January, 2007, San Jose, USA (Invited talk).

B.Q. Cao, M. Lorenz, A. Rahm, H. von Wenckstern, C. Czekalla, J. Lenzner, G. Benndorf, M. Grundmann, Phosphorus acceptor doped ZnO nanowires prepared by pulsed-laser deposition, Nanotechnology 18, 455707 (2007), see also Nanotechnology Highlight http://nanotechweb.org:80/cws/article/lab/31609

M. Lorenz, Gepulste Laser-Plasmaabscheidung (PLD) von oxidischen Dünnfilm- und Nanostrukturen, Habil. Thesis, Universität Leipzig, Fakultät für Physik und Geowissenschaften 2007.

A. Rahm, Growth and Characterization of ZnO-based Nanostructures, PhD thesis, Universität Leipzig, Fakultät für Physik und Geowissenschaften 2007.

T. Nobis, A. Rahm, C. Czekalla, M. Lorenz, M. Grundmann, Optical whispering gallery modes in dodecagonal zinc oxide microcrystals, Superlattices and Microstructures (2007), doi:10.1016/j.spmi.2007.04.031 in press

A. O. Ankiewicz, W. Gehlhoff, E. M. Kaidashev, A. Rahm, M. Lorenz, M. Grundmann, M. C. Carmo and N. A. Sobolev, Electron Paramagnetic Resonance Characterization of Mn–and Co–Doped ZnO Nanowires, AIP Conference Proceedings CP893, Physics of Semiconductors, 28th Int. Conf., eds. W. Jantsch, F. Schäffler (2007) p. 63.

R. Schmidt-Grund, B. Rheinländer, C. Czekalla, G. Benndorf, H. Hochmuth, M. Lorenz, and M. Grundmann, Exciton-polariton formation at room temperature in a planar ZnO resonator structure, submitted (2007)

J. Zúñiga Pérez, A. Rahm, C. Czekalla, J. Lenzner, M. Lorenz, M. Grundmann, Ordered growth of tilted ZnO nanowires: morphological, structural and optical characterization, Nanotechnology 18, 195303 (2007)

M. Lorenz, Pulsed Laser Deposition of ZnO-based Thin Films, chapter 7 in: A. Klein, K. Ellmer (eds.) "Zinc Oxide as Transparent Electronic Material and its Application in Thin Film Solar Cells" (Springer, Berlin, 2007) 307-359 in press.

A. O. Ankiewicz, M. C. Carmo, N. A. Sobolev, W. Gehlhoff, E. M. Kaydashev, A. Rahm, M. Lorenz, M. Grundmann Electron Paramagnetic Resonance in TM-doped ZnO Nanowires, Journal of Applied Physics 101, 024324 (2007)

M. Grundmann, A. Rahm, Th. Nobis, H. v. Wenckstern, M. Lorenz, C. Czekalla, J. Lenzner, Growth and Characterization of Optical and Electrical Properties of ZnO Nano- and Microwires, Proc. MRS 957 (2007), in press

R. Schmidt-Grund, B. Rheinländer, C. Czekalla, G. Benndorf, H. Hochmut, A. Rahm, M. Lorenz, and M. Grundmann, ZnO based planar and micro-pillar resonators, Superlattices and Microstrutures 41 (2007) 360-363.

A. Rahm, M. Lorenz, Th. Nobis, G. Zimmermann, M. Grundmann, B. Fuhrmann, F. Syrowatka, Pulsed Laser Deposition and characterization of ZnO nanowires with regular lateral arrangement, Applied Physics A: Materials Science and Processing 88 (2007) 31-34.

Cathodoluminescence of single ZnO nanorod heterostructures, by Bernard Piechal, Jinkyoung Yoo, Abdelhamid Elshaer, Augustine Che Mofor, Gyu-Chul Yi, Andrey Bakin, Andreas Waag, Fabrice Donatini, and Le Si Dang, Phys. Stat. Sol. (b) 244, 1458 (2007).

Luminescence of Localized Excitons in ZnO/MgZnO Nanowire Quantum Well Heterostructures J. Guignard, M. Lorenz, C. Hanisch, E. M. Kaydashev, M. Grundmann, F. Donatini, Le Si Dang accepted for oral presentation at 13th Int. Conf. on II-VI Compounds, September 2007, Jeju, Korea

Low temperature growth of single-crystal ZnO nanorods N Boukos, C Chandrinou, C Stogios, K Giannakopoulos and A Travlos Nanotechnology 18 275601 (2007)

Structural and photoluminescence properties of ZnO nanoparticles on silicon oxide Giannakopoulos K, Boukos N, Travlos A, Monteiro T, Soares MJ, Peres M, Neves A, Carmo MC Applied Physics A: Materials Science and Processing 88, 41, (2007)

Growth of ZnO nanorods by a simple chemical method Boukos N, Chandrinou C, Giannakopoulos K, Pistolis G, Travlos A Applied Physics A: Materials Science and Processing 88, 35, (2007)

2006

M. Al-Suleiman, A. Che Mofor, A. El-Shaer, A. Bakin, H.-H. Wehmann, A. Waag: Photoluminescence properties: Catalyst-free ZnO nanorods and layers versus bulk ZnO; Appl. Phys. Lett. 89 (2006) 231911-231913

L. Wischmeier, T. Voss, I. Rückmann, J. Gutowski, A. C. Mofor, A. Bakin, A. Waag: Photoluminescence dynamics of surface-related emission in ZnO nanorods, 4th International Workshop on ZnO and Related Materials, Gießen (2006) (Talk)

A. Che Mofor, A. Bakin, A. El-Shaer, M. Al-Suleiman, N. Boukos , A. Travlos, and A. Waag: VPT Growth of ZnO: From Nanostructures to Layers 4th International Workshop on ZnO and Related Materials, Gießen (2006) (Poster)

C. Bekeny, L. Wischmeier, B. Hilker, T. Voss, B. Postels, A. C. Mofor, M. Kreye, A. Bakin, A. Waag: Origin of the near band-edge photoluminescence in ZnO nanorods fabricated by equeous chemical growth and vapour phase epitaxy, 4th International Workshop on ZnO and Related Materials, Gießen (2006) (Poster)

A. C. Mofor, A. El-Shaer, M. Suleiman, A. Bakin, A. Waag: Fabrication of ZnO Nanorod-based Single Quantum Well Structures, European Material Research Society Fall meeting, 4-8 September 2006, Warsaw Poland (Talk)

B. Piechal, J. Yoo, A. El-Shaer, A. C. Mofor, G.-C. Yi, A. Bakin, A. Waag, F. Donatini, D. Le Si: Cathodoluminescence study of wide band gap ZnO nanorod heterostructures, European Material Research Society Fall meeting, 4-8 September 2006, Warsaw Poland (Invited talk)

A. Bakin: ZnO Nanostructures, European Material Research Society Fall meeting, 4-8 September 2006, Warsaw Poland (Invited Plenary Talk)

E. Schlenker, A. Bakin, B. Postels, A.C. Mofor, H.-H. Wehmann, T. Weimann, P. Hinze, A. Waag: Electrical characterization of ZnO–nanostructures, European Material Research Society Fall meeting, 4-8 September 2006, Warsaw Poland

L. Wischmeier, T. Voss, I. Rückmann, J. Gutowski, A. C. Mofor, A. Bakin, A. Waag: Photoluminescence dynamics of surface-related emission in VPE grown ZnO nanowires, 28th Internation Conference on the Physics of Semiconductors (ICPS), Vienna (2006) (Poster)

A. Waag, A. Elshaer, A. C. Mofor, M. Suleimann, B. Postels, E. Schlenker, H. Wehmann, A. Bakin: MBE-grown ZnMgO-ZnO quantum wells embedded into ZnO nanopillars, Material Research Society (MRS) Conference, 27th Nov - 1 Dec 2006, Boston, Massachussetts, USA (Talk)

B. Postels, M. Kreye, H.-H. Wehmann, A. Bakin, N. Boukos, A. Travlos, A. Waag: Selective growth of ZnO nanorods in aqueous solution, E-MRS Spring meeting, Nice (2006) (Poster)

B. Postels, M. Kreye, H.-H. Wehmann, a.Waag: Advanced and selective growth of ZnO nanopillars in wet chemical solution, DPG Spring meeting, Dresden (2006)

A. Waag, A. El-Shaer, A.C. Mofor, M. Al-Suleiman, B. Postels, E. Schlenker, H.-H. Wehmann, A. Bakin: ZnO based Nanostructures for Optoelectronics; 6th Intern. Conf. on Physics of Light-Matter Coupling in Nanostructures (PLMCN6), Magdeburg, 25. - 29. September 2006 (Invited Talk)

M. Al-Suleiman, A. El-Shaer, A. Che Mofor, A.Bakin, H.-H.Wehmann, A.Waag: Optical properties of ZnMgO-ZnO quantum wells; 6th Intern. Conf. on Physics of Light-Matter Coupling in Nanostructures (PLMCN6), Magdeburg, 25. - 29. September 2006 (P1.11) (Poster)

P. Kalson, Q.X. Zhao and M. Willander: ZnO nanorods grown on different substrates, 4th International Workshop on ZnO and Related Materials, Gießen (2006) (Poster)

T. Moe Børseth, B. G. Svensson, A. Yu. Kuznetsov, P. Klason, Q. X. Zhao, and M. Willander, Applied Physics Letters 89, 262112 (2006).

M. Willander et al., "Microtechnology meets Nanotechnology". International meeting on Science and Technology, 30th August-2nd Sept, 2006. Brazil (Invited talk).

M. Willander et al., The Electrochemical Society Meeting, Cancun, Mexico, 29 Oct. - 3 Nov., 2006 (Invited talk).

M. Willander, 3 day course on "Nanooptics and Nanoelecronics" for participants in 4th Peruan Congress on Science and Technology of Materials, Lima, 12-14 Nov. 2006.

Q.X. Zhao, P. Kalson and M. Willander ,”Growth of ZnO Nanostructures by Vapor-Liquid Solid Method", Applied Physics A on Jan. 13, 2007.

Q.X. Zhao, P. Klason and M. Willander, P.J. Bergman, W.L. Jiang, and J.H. Yang, “Synthesis and Characterization of ZnO Nanostructures Grown on Si Substrates” Physica Script T126, Sept. (2006) 131-134.

Klason, P.; Magnusson, K.; Nur, O.; Zhao, Q.X.; Wahab, Q.U.; Willander, M., “Synthesis and structural and optical properties of ZnO micro- and nanostructures grown by the vapour-liquid-solid method”, Physica Scripta, v 2006, n T126, Sept. 2006, p 53-6.

T. Nobis, A. Rahm, M. Lorenz, M. Grundmann, Numerical Modelling of Zinc Oxide Nanocavities to Determine Their Birefringence, Proc. SPIE 6122, 61220V (2006)

A.Rahm, E. M. Kaidashev, H. Schmidt, M. Diaconu, A. Pöppl, R. Böttcher, C. Meinecke, T. Butz, M. Lorenz, M. Grundmann, Growth and characterization of Mn- and Co-doped ZnO nanowires, Microchimica Acta 156 No. 1-2 (2007) 21-26, published online May 26, 2006.

Zinc oxide nanoparticles on silicon K Giannakopoulos, N Boukos and A Travlos, Superlattices and Microstructures, 39, 115-123,(2006)

VPT Growth of ZnO: From Nanostructures to Layers A. Che Mofor, A. Bakin, A. El-Shaer, M. Al-Suleiman, N. Boukos, A. Travlos, and A. Waag The 4th International Workshop on ZnO and Related Materials, Giessen Germany, 2006

ZnO Nanopillar-based Heterostructures for device applications A. Bakin, A. Che Mofor, A. Elshaer, M. Al-Suleiman, E. Schlenker, N. Boukos, A. Travlos, A. Waag The 4th International Workshop on ZnO and Related Materials, Giessen Germany, 2006

2005

M. Grundmann, H. von Wenckstern, R. Pickenhain, Th. Nobis, A. Rahm, M. Lorenz, Electrical properties of ZnO thin films and optical properties of ZnO-based nanostructures, Superlattices and Microstructures 38, 317-328 (2005)

M. Lorenz, E.M. Kaidashev, A. Rahm, Th. Nobis, J. Lenzner, G. Wagner, D. Spemann, H. Hochmuth, M. Grundmann, MgxZn1-xO (0<=x<0.2) nanowire arrays on sapphire grown by high-pressure pulsed-laser deposition Appl. Phys. Lett. 86, 143113 (2005)

Th. Nobis, E.M. Kaidashev, A. Rahm, M. Lorenz, M. Grundmann, Optical properties of single ZnO nanocolumns and nanoneedles, Proc. of the NATO Advanced Research Workshop 'ZnO as a material for micro- and optoelectronic applications', H. Nickel, E. Terukov, eds., in Zinc Oxide - a Material for Micro- and Optoelectronic Applications (Springer, Berlin, 2005) 83-98.

A. Rahm, G.W. Yang, M. Lorenz, T. Nobis, J. Lenzner, G. Wagner, M. Grundmann, Two-dimensional ZnO:Al nanosheets and nanowalls obtained by Al2O3-assisted thermal evaporation, Thin Solid Films 486, 191-194 (2005)

T. Nobis, E. M. Kaidashev, A. Rahm, M. Lorenz, J. Lenzner, M.Grundmann, Optical Resonances Of Single Zinc Oxide Microcrystals, Proc. Int. Conf. on the Physics of Semiconductors (ICPS-27), Flagstaff, AZ, USA, 2004, eds. J. Menéndez, C. G. Van de Walle, AIP Conference Proceedings 772 (2005)

A. Rahm, T. Nobis, E. M. Kaidashev, M. Lorenz, G. Wagner, J. Lenzner, M. Grundmann, High-pressure Pulsed Laser Deposition and Structural Characterization of Zinc Oxide Nanowires, Proc. Int. Conf. on the Physics of Semiconductors (ICPS-27), Flagstaff, AZ, USA, 2004, eds. J. Menéndez, C. G. Van de Walle, AIP Conference Proceedings 772 (2005)

2004

Thomas Nobis, Evgeni M. Kaidashev, Andreas Rahm, Michael Lorenz, Marius Grundmann, Whispering gallery modes in nano-sized dielectric resonators with hexagonal cross section, Phys. Rev. Lett. 93, 103903 (2004)

Thomas Nobis, Evgeni M. Kaidashev, Andreas Rahm, Michael Lorenz, Jörg Lenzner, Marius Grundmann, Spatially inhomogeneous impurity distribution in ZnO micropillars, Nano Lett. 4, 797 (2004)

M. Lorenz, J. Lenzner, E.M. Kaidashev, H. Hochmuth, M. Grundmann, Cathodoluminescence of selected single ZnO nanowires on sapphire, Annalen der Physik (Leipzig) 13 No. 1-2 (2004) 39-42.